A resin pelletizer apparatus is an apparatus such that, with use of rotary blades that rotate at a high speed on a die surface having die holes formed therein, a molten resin having a strand shape (string shape) extruded from the die holes into water is cut, whereby the resin is shaped into a pellet form.
In the resin pelletizer apparatus, poor cutting of the molten resin may occur. The poor cutting refers to a phenomenon in which, for example, a pellet having a whisker-shaped portion is generated, or a plurality of pellets connected in a chain form are generated.
In order to prevent poor cutting, the following technique, for example, is proposed. Patent Literature 1 discloses a poor cutting detection method including a step of measuring the position of a cutter knife by allowing the cutter knife to abut against the die surface at each timing of standard position setting and setting the measured position as a standard position, a step of measuring the position of the cutter knife while rotating the cutter knife to cut the molten resin and setting the measured position as a current position, and a step of notifying a user of the occurrence of poor cutting with an alarm when a difference between the current position and the standard position becomes larger than a predetermined set value of clearance.
Patent Literature 2 discloses a method of detecting a molten resin pressure in the inside of the die to change a bias value and controlling the pressing force of a cutter driving shaft. According to this method, an optimal cutting operation can be obtained in accordance with the change in the molten resin pressure.
Development of a further technique that can prevent poor cutting is demanded.